Texture/Material Import issues

I’m fairly new to UE4 and I began by improving my texturing skills and getting a better understanding of the material editor but I have ran into an issue that involves the alpha channel on my texture.

When I first made the texture I applied it to the landscape to see what it would look like (Image below).
The orange bits are slightly glowing.

I then decided to make some changes to the diffuse and normal maps but not the emissive (orange squares) so nothing should have changed. I then re-imported my textures and changed a few values in the material but now my Emissive texture looks like this…
and when applied to the material…

Any advice on this little problem I’ve ran in to would be great and much appreciated.

You don’t need a separate texture just for a solid color, if you need a color then use a Constant3 node
You can then place the alpha texture in your alpha channel in the diffuse texture, if you’re already using an alpha then you would need to make a new texture.
Remember, you can combine grayscale images into a single texture map by putting them into the different color channels. When you setup your material in UE4 you then have an output of each color channel that you can specifically use. And if you need to color it, say you have a mask for the emissive color you can just multiply it by a Constant3 to apply the color.